Tom is a loner who shows little interest in making friends and does not exhibit much emotion. However, he is efficient at his job. His job involves updating a database to reflect the most recent events occurring in the world. He is showing signs of _________.

A) schizotypal personality disorder
B) antisocial personality disorder
C) schizoid personality disorder
D) illness anxiety disorder

Tom exhibits the symptoms of schizoid personality disorder, which is characterized by a lack of interest in forming close relationships, a preference for solitary activities, and emotional detachment. This is different from schizotypal personality disorder, which is characterized by odd or eccentric behavior, beliefs, and perceptions. Antisocial personality disorder involves a disregard for the rights of others and a lack of empathy, which does not seem to be the case with Tom. Illness anxiety disorder involves preoccupation with having or acquiring a serious illness, which is not applicable to Tom's situation.